xref: /linux/drivers/net/bareudp.c (revision e6409584dec6d67f5aa9e2e0f55e2c5f0f55d63f)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Bareudp: UDP  tunnel encasulation for different Payload types like
3  * MPLS, NSH, IP, etc.
4  * Copyright (c) 2019 Nokia, Inc.
5  * Authors:  Martin Varghese, <martin.varghese@nokia.com>
6  */
7 
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/etherdevice.h>
13 #include <linux/hash.h>
14 #include <net/dst_metadata.h>
15 #include <net/gro_cells.h>
16 #include <net/rtnetlink.h>
17 #include <net/protocol.h>
18 #include <net/ip6_tunnel.h>
19 #include <net/ip_tunnels.h>
20 #include <net/udp_tunnel.h>
21 #include <net/bareudp.h>
22 
23 #define BAREUDP_BASE_HLEN sizeof(struct udphdr)
24 #define BAREUDP_IPV4_HLEN (sizeof(struct iphdr) + \
25 			   sizeof(struct udphdr))
26 #define BAREUDP_IPV6_HLEN (sizeof(struct ipv6hdr) + \
27 			   sizeof(struct udphdr))
28 
29 static bool log_ecn_error = true;
30 module_param(log_ecn_error, bool, 0644);
31 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
32 
33 /* per-network namespace private data for this module */
34 
35 static unsigned int bareudp_net_id;
36 
37 struct bareudp_net {
38 	struct list_head        bareudp_list;
39 };
40 
41 struct bareudp_conf {
42 	__be16 ethertype;
43 	__be16 port;
44 	u16 sport_min;
45 	bool multi_proto_mode;
46 };
47 
48 /* Pseudo network device */
49 struct bareudp_dev {
50 	struct net         *net;        /* netns for packet i/o */
51 	struct net_device  *dev;        /* netdev for bareudp tunnel */
52 	__be16		   ethertype;
53 	__be16             port;
54 	u16	           sport_min;
55 	bool               multi_proto_mode;
56 	struct sock        __rcu *sk;
57 	struct list_head   next;        /* bareudp node  on namespace list */
58 	struct gro_cells   gro_cells;
59 };
60 
61 static int bareudp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
62 {
63 	struct metadata_dst *tun_dst = NULL;
64 	IP_TUNNEL_DECLARE_FLAGS(key) = { };
65 	struct bareudp_dev *bareudp;
66 	unsigned short family;
67 	unsigned int len;
68 	__be16 proto;
69 	void *oiph;
70 	int err;
71 	int nh;
72 
73 	bareudp = rcu_dereference_sk_user_data(sk);
74 	if (!bareudp)
75 		goto drop;
76 
77 	if (skb->protocol ==  htons(ETH_P_IP))
78 		family = AF_INET;
79 	else
80 		family = AF_INET6;
81 
82 	if (bareudp->ethertype == htons(ETH_P_IP)) {
83 		__u8 ipversion;
84 
85 		if (skb_copy_bits(skb, BAREUDP_BASE_HLEN, &ipversion,
86 				  sizeof(ipversion))) {
87 			dev_dstats_rx_dropped(bareudp->dev);
88 			goto drop;
89 		}
90 		ipversion >>= 4;
91 
92 		if (ipversion == 4) {
93 			proto = htons(ETH_P_IP);
94 		} else if (ipversion == 6 && bareudp->multi_proto_mode) {
95 			proto = htons(ETH_P_IPV6);
96 		} else {
97 			dev_dstats_rx_dropped(bareudp->dev);
98 			goto drop;
99 		}
100 	} else if (bareudp->ethertype == htons(ETH_P_MPLS_UC)) {
101 		struct iphdr *tunnel_hdr;
102 
103 		tunnel_hdr = (struct iphdr *)skb_network_header(skb);
104 		if (tunnel_hdr->version == 4) {
105 			if (!ipv4_is_multicast(tunnel_hdr->daddr)) {
106 				proto = bareudp->ethertype;
107 			} else if (bareudp->multi_proto_mode &&
108 				   ipv4_is_multicast(tunnel_hdr->daddr)) {
109 				proto = htons(ETH_P_MPLS_MC);
110 			} else {
111 				dev_dstats_rx_dropped(bareudp->dev);
112 				goto drop;
113 			}
114 		} else {
115 			int addr_type;
116 			struct ipv6hdr *tunnel_hdr_v6;
117 
118 			tunnel_hdr_v6 = (struct ipv6hdr *)skb_network_header(skb);
119 			addr_type =
120 			ipv6_addr_type((struct in6_addr *)&tunnel_hdr_v6->daddr);
121 			if (!(addr_type & IPV6_ADDR_MULTICAST)) {
122 				proto = bareudp->ethertype;
123 			} else if (bareudp->multi_proto_mode &&
124 				   (addr_type & IPV6_ADDR_MULTICAST)) {
125 				proto = htons(ETH_P_MPLS_MC);
126 			} else {
127 				dev_dstats_rx_dropped(bareudp->dev);
128 				goto drop;
129 			}
130 		}
131 	} else {
132 		proto = bareudp->ethertype;
133 	}
134 
135 	if (iptunnel_pull_header(skb, BAREUDP_BASE_HLEN,
136 				 proto,
137 				 !net_eq(bareudp->net,
138 				 dev_net(bareudp->dev)))) {
139 		dev_dstats_rx_dropped(bareudp->dev);
140 		goto drop;
141 	}
142 
143 	__set_bit(IP_TUNNEL_KEY_BIT, key);
144 
145 	tun_dst = udp_tun_rx_dst(skb, family, key, 0, 0);
146 	if (!tun_dst) {
147 		dev_dstats_rx_dropped(bareudp->dev);
148 		goto drop;
149 	}
150 	skb_dst_set(skb, &tun_dst->dst);
151 	skb->dev = bareudp->dev;
152 	skb_reset_mac_header(skb);
153 
154 	/* Save offset of outer header relative to skb->head,
155 	 * because we are going to reset the network header to the inner header
156 	 * and might change skb->head.
157 	 */
158 	nh = skb_network_header(skb) - skb->head;
159 
160 	skb_reset_network_header(skb);
161 
162 	if (!pskb_inet_may_pull(skb)) {
163 		DEV_STATS_INC(bareudp->dev, rx_length_errors);
164 		DEV_STATS_INC(bareudp->dev, rx_errors);
165 		goto drop;
166 	}
167 
168 	/* Get the outer header. */
169 	oiph = skb->head + nh;
170 
171 	if (!ipv6_mod_enabled() || family == AF_INET)
172 		err = IP_ECN_decapsulate(oiph, skb);
173 	else
174 		err = IP6_ECN_decapsulate(oiph, skb);
175 
176 	if (unlikely(err)) {
177 		if (log_ecn_error) {
178 			if  (!ipv6_mod_enabled() || family == AF_INET)
179 				net_info_ratelimited("non-ECT from %pI4 "
180 						     "with TOS=%#x\n",
181 						     &((struct iphdr *)oiph)->saddr,
182 						     ((struct iphdr *)oiph)->tos);
183 			else
184 				net_info_ratelimited("non-ECT from %pI6\n",
185 						     &((struct ipv6hdr *)oiph)->saddr);
186 		}
187 		if (err > 1) {
188 			DEV_STATS_INC(bareudp->dev, rx_frame_errors);
189 			DEV_STATS_INC(bareudp->dev, rx_errors);
190 			goto drop;
191 		}
192 	}
193 
194 	len = skb->len;
195 	err = gro_cells_receive(&bareudp->gro_cells, skb);
196 	if (likely(err == NET_RX_SUCCESS))
197 		dev_dstats_rx_add(bareudp->dev, len);
198 
199 	return 0;
200 drop:
201 	/* Consume bad packet */
202 	kfree_skb(skb);
203 
204 	return 0;
205 }
206 
207 static int bareudp_err_lookup(struct sock *sk, struct sk_buff *skb)
208 {
209 	return 0;
210 }
211 
212 static int bareudp_init(struct net_device *dev)
213 {
214 	struct bareudp_dev *bareudp = netdev_priv(dev);
215 	int err;
216 
217 	err = gro_cells_init(&bareudp->gro_cells, dev);
218 	if (err)
219 		return err;
220 
221 	return 0;
222 }
223 
224 static void bareudp_uninit(struct net_device *dev)
225 {
226 	struct bareudp_dev *bareudp = netdev_priv(dev);
227 
228 	gro_cells_destroy(&bareudp->gro_cells);
229 }
230 
231 static struct sock *bareudp_create_sock(struct net *net, __be16 port)
232 {
233 	struct udp_port_cfg udp_conf;
234 	struct socket *sock;
235 	int err;
236 
237 	memset(&udp_conf, 0, sizeof(udp_conf));
238 
239 	if (ipv6_mod_enabled())
240 		udp_conf.family = AF_INET6;
241 	else
242 		udp_conf.family = AF_INET;
243 
244 	udp_conf.local_udp_port = port;
245 	/* Open UDP socket */
246 	err = udp_sock_create(net, &udp_conf, &sock);
247 	if (err < 0)
248 		return ERR_PTR(err);
249 
250 	udp_allow_gso(sock->sk);
251 	return sock->sk;
252 }
253 
254 /* Create new listen socket if needed */
255 static int bareudp_socket_create(struct bareudp_dev *bareudp, __be16 port)
256 {
257 	struct udp_tunnel_sock_cfg tunnel_cfg;
258 	struct sock *sk;
259 
260 	sk = bareudp_create_sock(bareudp->net, port);
261 	if (IS_ERR(sk))
262 		return PTR_ERR(sk);
263 
264 	/* Mark socket as an encapsulation socket */
265 	memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
266 	tunnel_cfg.sk_user_data = bareudp;
267 	tunnel_cfg.encap_type = 1;
268 	tunnel_cfg.encap_rcv = bareudp_udp_encap_recv;
269 	tunnel_cfg.encap_err_lookup = bareudp_err_lookup;
270 	tunnel_cfg.encap_destroy = NULL;
271 	setup_udp_tunnel_sock(bareudp->net, sk, &tunnel_cfg);
272 
273 	rcu_assign_pointer(bareudp->sk, sk);
274 	return 0;
275 }
276 
277 static int bareudp_open(struct net_device *dev)
278 {
279 	struct bareudp_dev *bareudp = netdev_priv(dev);
280 
281 	return bareudp_socket_create(bareudp, bareudp->port);
282 }
283 
284 static void bareudp_sock_release(struct bareudp_dev *bareudp)
285 {
286 	struct sock *sk;
287 
288 	sk = rtnl_dereference(bareudp->sk);
289 	rcu_assign_pointer(bareudp->sk, NULL);
290 	udp_tunnel_sock_release(sk);
291 }
292 
293 static int bareudp_stop(struct net_device *dev)
294 {
295 	struct bareudp_dev *bareudp = netdev_priv(dev);
296 
297 	bareudp_sock_release(bareudp);
298 	return 0;
299 }
300 
301 static int bareudp_xmit_skb(struct sk_buff *skb, struct net_device *dev,
302 			    struct bareudp_dev *bareudp,
303 			    const struct ip_tunnel_info *info)
304 {
305 	bool udp_sum = test_bit(IP_TUNNEL_CSUM_BIT, info->key.tun_flags);
306 	bool xnet = !net_eq(bareudp->net, dev_net(bareudp->dev));
307 	bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
308 	struct sock *sk = rcu_dereference(bareudp->sk);
309 	const struct ip_tunnel_key *key = &info->key;
310 	struct rtable *rt;
311 	__be16 sport, df;
312 	int min_headroom;
313 	__u8 tos, ttl;
314 	__be32 saddr;
315 	int err;
316 
317 	if (skb_vlan_inet_prepare(skb, skb->protocol != htons(ETH_P_TEB)))
318 		return -EINVAL;
319 
320 	if (!sk)
321 		return -ESHUTDOWN;
322 
323 	sport = udp_flow_src_port(bareudp->net, skb,
324 				  bareudp->sport_min, USHRT_MAX,
325 				  true);
326 	rt = udp_tunnel_dst_lookup(skb, dev, bareudp->net, 0, &saddr, &info->key,
327 				   sport, bareudp->port, key->tos,
328 				   use_cache ?
329 				   (struct dst_cache *)&info->dst_cache : NULL);
330 
331 	if (IS_ERR(rt))
332 		return PTR_ERR(rt);
333 
334 	skb_tunnel_check_pmtu(skb, &rt->dst,
335 			      BAREUDP_IPV4_HLEN + info->options_len, false);
336 
337 	tos = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
338 	ttl = key->ttl;
339 	df = test_bit(IP_TUNNEL_DONT_FRAGMENT_BIT, key->tun_flags) ?
340 	     htons(IP_DF) : 0;
341 	skb_scrub_packet(skb, xnet);
342 
343 	err = -ENOSPC;
344 	if (!skb_pull(skb, skb_network_offset(skb)))
345 		goto free_dst;
346 
347 	min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len +
348 		BAREUDP_BASE_HLEN + info->options_len + sizeof(struct iphdr);
349 
350 	err = skb_cow_head(skb, min_headroom);
351 	if (unlikely(err))
352 		goto free_dst;
353 
354 	err = udp_tunnel_handle_offloads(skb, udp_sum);
355 	if (err)
356 		goto free_dst;
357 
358 	skb_set_inner_protocol(skb, bareudp->ethertype);
359 	udp_tunnel_xmit_skb(rt, sk, skb, saddr, info->key.u.ipv4.dst,
360 			    tos, ttl, df, sport, bareudp->port,
361 			    !net_eq(bareudp->net, dev_net(bareudp->dev)),
362 			    !test_bit(IP_TUNNEL_CSUM_BIT, info->key.tun_flags),
363 			    0);
364 	return 0;
365 
366 free_dst:
367 	dst_release(&rt->dst);
368 	return err;
369 }
370 
371 static int bareudp6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
372 			     struct bareudp_dev *bareudp,
373 			     const struct ip_tunnel_info *info)
374 {
375 	bool udp_sum = test_bit(IP_TUNNEL_CSUM_BIT, info->key.tun_flags);
376 	bool xnet = !net_eq(bareudp->net, dev_net(bareudp->dev));
377 	bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
378 	struct sock *sk = rcu_dereference(bareudp->sk);
379 	const struct ip_tunnel_key *key = &info->key;
380 	struct dst_entry *dst = NULL;
381 	struct in6_addr saddr, daddr;
382 	int min_headroom;
383 	__u8 prio, ttl;
384 	__be16 sport;
385 	int err;
386 
387 	if (skb_vlan_inet_prepare(skb, skb->protocol != htons(ETH_P_TEB)))
388 		return -EINVAL;
389 
390 	if (!sk)
391 		return -ESHUTDOWN;
392 
393 	sport = udp_flow_src_port(bareudp->net, skb,
394 				  bareudp->sport_min, USHRT_MAX,
395 				  true);
396 	dst = udp_tunnel6_dst_lookup(skb, dev, bareudp->net, sk, 0, &saddr,
397 				     key, sport, bareudp->port, key->tos,
398 				     use_cache ?
399 				     (struct dst_cache *) &info->dst_cache : NULL);
400 	if (IS_ERR(dst))
401 		return PTR_ERR(dst);
402 
403 	skb_tunnel_check_pmtu(skb, dst, BAREUDP_IPV6_HLEN + info->options_len,
404 			      false);
405 
406 	prio = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
407 	ttl = key->ttl;
408 
409 	skb_scrub_packet(skb, xnet);
410 
411 	err = -ENOSPC;
412 	if (!skb_pull(skb, skb_network_offset(skb)))
413 		goto free_dst;
414 
415 	min_headroom = LL_RESERVED_SPACE(dst->dev) + dst->header_len +
416 		BAREUDP_BASE_HLEN + info->options_len + sizeof(struct ipv6hdr);
417 
418 	err = skb_cow_head(skb, min_headroom);
419 	if (unlikely(err))
420 		goto free_dst;
421 
422 	err = udp_tunnel_handle_offloads(skb, udp_sum);
423 	if (err)
424 		goto free_dst;
425 
426 	daddr = info->key.u.ipv6.dst;
427 	udp_tunnel6_xmit_skb(dst, sk, skb, dev,
428 			     &saddr, &daddr, prio, ttl,
429 			     info->key.label, sport, bareudp->port,
430 			     !test_bit(IP_TUNNEL_CSUM_BIT,
431 				       info->key.tun_flags),
432 			     0);
433 	return 0;
434 
435 free_dst:
436 	dst_release(dst);
437 	return err;
438 }
439 
440 static bool bareudp_proto_valid(struct bareudp_dev *bareudp, __be16 proto)
441 {
442 	if (bareudp->ethertype == proto)
443 		return true;
444 
445 	if (!bareudp->multi_proto_mode)
446 		return false;
447 
448 	if (bareudp->ethertype == htons(ETH_P_MPLS_UC) &&
449 	    proto == htons(ETH_P_MPLS_MC))
450 		return true;
451 
452 	if (bareudp->ethertype == htons(ETH_P_IP) &&
453 	    proto == htons(ETH_P_IPV6))
454 		return true;
455 
456 	return false;
457 }
458 
459 static netdev_tx_t bareudp_xmit(struct sk_buff *skb, struct net_device *dev)
460 {
461 	struct bareudp_dev *bareudp = netdev_priv(dev);
462 	struct ip_tunnel_info *info = NULL;
463 	int err;
464 
465 	if (!bareudp_proto_valid(bareudp, skb->protocol)) {
466 		err = -EINVAL;
467 		goto tx_error;
468 	}
469 
470 	info = skb_tunnel_info(skb);
471 	if (unlikely(!info || !(info->mode & IP_TUNNEL_INFO_TX))) {
472 		err = -EINVAL;
473 		goto tx_error;
474 	}
475 
476 	rcu_read_lock();
477 	if (ipv6_mod_enabled() && info->mode & IP_TUNNEL_INFO_IPV6)
478 		err = bareudp6_xmit_skb(skb, dev, bareudp, info);
479 	else
480 		err = bareudp_xmit_skb(skb, dev, bareudp, info);
481 
482 	rcu_read_unlock();
483 
484 	if (likely(!err))
485 		return NETDEV_TX_OK;
486 tx_error:
487 	dev_kfree_skb(skb);
488 
489 	if (err == -ELOOP)
490 		DEV_STATS_INC(dev, collisions);
491 	else if (err == -ENETUNREACH)
492 		DEV_STATS_INC(dev, tx_carrier_errors);
493 
494 	DEV_STATS_INC(dev, tx_errors);
495 	return NETDEV_TX_OK;
496 }
497 
498 static int bareudp_fill_metadata_dst(struct net_device *dev,
499 				     struct sk_buff *skb)
500 {
501 	struct ip_tunnel_info *info = skb_tunnel_info(skb);
502 	struct bareudp_dev *bareudp = netdev_priv(dev);
503 	bool use_cache;
504 	__be16 sport;
505 
506 	use_cache = ip_tunnel_dst_cache_usable(skb, info);
507 	sport = udp_flow_src_port(bareudp->net, skb,
508 				  bareudp->sport_min, USHRT_MAX,
509 				  true);
510 
511 	if (!ipv6_mod_enabled() || ip_tunnel_info_af(info) == AF_INET) {
512 		struct rtable *rt;
513 		__be32 saddr;
514 
515 		rt = udp_tunnel_dst_lookup(skb, dev, bareudp->net, 0, &saddr,
516 					   &info->key, sport, bareudp->port,
517 					   info->key.tos,
518 					   use_cache ? &info->dst_cache : NULL);
519 		if (IS_ERR(rt))
520 			return PTR_ERR(rt);
521 
522 		ip_rt_put(rt);
523 		info->key.u.ipv4.src = saddr;
524 	} else if (ip_tunnel_info_af(info) == AF_INET6) {
525 		struct dst_entry *dst;
526 		struct in6_addr saddr;
527 		struct sock *sk;
528 
529 		sk = rcu_dereference(bareudp->sk);
530 		if (!sk)
531 			return -ESHUTDOWN;
532 
533 		dst = udp_tunnel6_dst_lookup(skb, dev, bareudp->net, sk,
534 					     0, &saddr, &info->key,
535 					     sport, bareudp->port, info->key.tos,
536 					     use_cache ? &info->dst_cache : NULL);
537 		if (IS_ERR(dst))
538 			return PTR_ERR(dst);
539 
540 		dst_release(dst);
541 		info->key.u.ipv6.src = saddr;
542 	} else {
543 		return -EINVAL;
544 	}
545 
546 	info->key.tp_src = sport;
547 	info->key.tp_dst = bareudp->port;
548 	return 0;
549 }
550 
551 static const struct net_device_ops bareudp_netdev_ops = {
552 	.ndo_init               = bareudp_init,
553 	.ndo_uninit             = bareudp_uninit,
554 	.ndo_open               = bareudp_open,
555 	.ndo_stop               = bareudp_stop,
556 	.ndo_start_xmit         = bareudp_xmit,
557 	.ndo_fill_metadata_dst  = bareudp_fill_metadata_dst,
558 };
559 
560 static const struct nla_policy bareudp_policy[IFLA_BAREUDP_MAX + 1] = {
561 	[IFLA_BAREUDP_PORT]                = { .type = NLA_U16 },
562 	[IFLA_BAREUDP_ETHERTYPE]	   = { .type = NLA_U16 },
563 	[IFLA_BAREUDP_SRCPORT_MIN]         = { .type = NLA_U16 },
564 	[IFLA_BAREUDP_MULTIPROTO_MODE]     = { .type = NLA_FLAG },
565 };
566 
567 /* Info for udev, that this is a virtual tunnel endpoint */
568 static const struct device_type bareudp_type = {
569 	.name = "bareudp",
570 };
571 
572 /* Initialize the device structure. */
573 static void bareudp_setup(struct net_device *dev)
574 {
575 	dev->netdev_ops = &bareudp_netdev_ops;
576 	dev->needs_free_netdev = true;
577 	SET_NETDEV_DEVTYPE(dev, &bareudp_type);
578 	dev->features    |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_FRAGLIST;
579 	dev->features    |= NETIF_F_RXCSUM;
580 	dev->features    |= NETIF_F_GSO_SOFTWARE;
581 	dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_FRAGLIST;
582 	dev->hw_features |= NETIF_F_RXCSUM;
583 	dev->hw_features |= NETIF_F_GSO_SOFTWARE;
584 	dev->hard_header_len = 0;
585 	dev->addr_len = 0;
586 	dev->mtu = ETH_DATA_LEN;
587 	dev->min_mtu = IPV4_MIN_MTU;
588 	dev->max_mtu = IP_MAX_MTU - BAREUDP_BASE_HLEN;
589 	dev->type = ARPHRD_NONE;
590 	netif_keep_dst(dev);
591 	dev->priv_flags |= IFF_NO_QUEUE;
592 	dev->lltx = true;
593 	dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
594 	dev->pcpu_stat_type = NETDEV_PCPU_STAT_DSTATS;
595 }
596 
597 static int bareudp_validate(struct nlattr *tb[], struct nlattr *data[],
598 			    struct netlink_ext_ack *extack)
599 {
600 	if (!data) {
601 		NL_SET_ERR_MSG(extack,
602 			       "Not enough attributes provided to perform the operation");
603 		return -EINVAL;
604 	}
605 	return 0;
606 }
607 
608 static int bareudp2info(struct nlattr *data[], struct bareudp_conf *conf,
609 			struct netlink_ext_ack *extack)
610 {
611 	memset(conf, 0, sizeof(*conf));
612 
613 	if (!data[IFLA_BAREUDP_PORT]) {
614 		NL_SET_ERR_MSG(extack, "port not specified");
615 		return -EINVAL;
616 	}
617 	if (!data[IFLA_BAREUDP_ETHERTYPE]) {
618 		NL_SET_ERR_MSG(extack, "ethertype not specified");
619 		return -EINVAL;
620 	}
621 
622 	conf->port = nla_get_u16(data[IFLA_BAREUDP_PORT]);
623 	conf->ethertype = nla_get_u16(data[IFLA_BAREUDP_ETHERTYPE]);
624 
625 	if (data[IFLA_BAREUDP_SRCPORT_MIN])
626 		conf->sport_min =  nla_get_u16(data[IFLA_BAREUDP_SRCPORT_MIN]);
627 
628 	if (data[IFLA_BAREUDP_MULTIPROTO_MODE])
629 		conf->multi_proto_mode = true;
630 
631 	return 0;
632 }
633 
634 static struct bareudp_dev *bareudp_find_dev(struct bareudp_net *bn,
635 					    const struct bareudp_conf *conf)
636 {
637 	struct bareudp_dev *bareudp, *t = NULL;
638 
639 	list_for_each_entry(bareudp, &bn->bareudp_list, next) {
640 		if (conf->port == bareudp->port)
641 			t = bareudp;
642 	}
643 	return t;
644 }
645 
646 static int bareudp_configure(struct net *net, struct net_device *dev,
647 			     struct bareudp_conf *conf,
648 			     struct netlink_ext_ack *extack)
649 {
650 	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
651 	struct bareudp_dev *t, *bareudp = netdev_priv(dev);
652 	int err;
653 
654 	bareudp->net = net;
655 	bareudp->dev = dev;
656 	t = bareudp_find_dev(bn, conf);
657 	if (t) {
658 		NL_SET_ERR_MSG(extack, "Another bareudp device using the same port already exists");
659 		return -EBUSY;
660 	}
661 
662 	if (conf->multi_proto_mode &&
663 	    (conf->ethertype != htons(ETH_P_MPLS_UC) &&
664 	     conf->ethertype != htons(ETH_P_IP))) {
665 		NL_SET_ERR_MSG(extack, "Cannot set multiproto mode for this ethertype (only IPv4 and unicast MPLS are supported)");
666 		return -EINVAL;
667 	}
668 
669 	bareudp->port = conf->port;
670 	bareudp->ethertype = conf->ethertype;
671 	bareudp->sport_min = conf->sport_min;
672 	bareudp->multi_proto_mode = conf->multi_proto_mode;
673 
674 	err = register_netdevice(dev);
675 	if (err)
676 		return err;
677 
678 	list_add(&bareudp->next, &bn->bareudp_list);
679 	return 0;
680 }
681 
682 static int bareudp_link_config(struct net_device *dev,
683 			       struct nlattr *tb[])
684 {
685 	int err;
686 
687 	if (tb[IFLA_MTU]) {
688 		err = dev_set_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
689 		if (err)
690 			return err;
691 	}
692 	return 0;
693 }
694 
695 static void bareudp_dellink(struct net_device *dev, struct list_head *head)
696 {
697 	struct bareudp_dev *bareudp = netdev_priv(dev);
698 
699 	list_del(&bareudp->next);
700 	unregister_netdevice_queue(dev, head);
701 }
702 
703 static int bareudp_newlink(struct net_device *dev,
704 			   struct rtnl_newlink_params *params,
705 			   struct netlink_ext_ack *extack)
706 {
707 	struct net *link_net = rtnl_newlink_link_net(params);
708 	struct nlattr **data = params->data;
709 	struct nlattr **tb = params->tb;
710 	struct bareudp_conf conf;
711 	int err;
712 
713 	err = bareudp2info(data, &conf, extack);
714 	if (err)
715 		return err;
716 
717 	err = bareudp_configure(link_net, dev, &conf, extack);
718 	if (err)
719 		return err;
720 
721 	err = bareudp_link_config(dev, tb);
722 	if (err)
723 		goto err_unconfig;
724 
725 	return 0;
726 
727 err_unconfig:
728 	bareudp_dellink(dev, NULL);
729 	return err;
730 }
731 
732 static size_t bareudp_get_size(const struct net_device *dev)
733 {
734 	return  nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_PORT */
735 		nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_ETHERTYPE */
736 		nla_total_size(sizeof(__u16))  +  /* IFLA_BAREUDP_SRCPORT_MIN */
737 		nla_total_size(0)              +  /* IFLA_BAREUDP_MULTIPROTO_MODE */
738 		0;
739 }
740 
741 static int bareudp_fill_info(struct sk_buff *skb, const struct net_device *dev)
742 {
743 	struct bareudp_dev *bareudp = netdev_priv(dev);
744 
745 	if (nla_put_be16(skb, IFLA_BAREUDP_PORT, bareudp->port))
746 		goto nla_put_failure;
747 	if (nla_put_be16(skb, IFLA_BAREUDP_ETHERTYPE, bareudp->ethertype))
748 		goto nla_put_failure;
749 	if (nla_put_u16(skb, IFLA_BAREUDP_SRCPORT_MIN, bareudp->sport_min))
750 		goto nla_put_failure;
751 	if (bareudp->multi_proto_mode &&
752 	    nla_put_flag(skb, IFLA_BAREUDP_MULTIPROTO_MODE))
753 		goto nla_put_failure;
754 
755 	return 0;
756 
757 nla_put_failure:
758 	return -EMSGSIZE;
759 }
760 
761 static struct rtnl_link_ops bareudp_link_ops __read_mostly = {
762 	.kind           = "bareudp",
763 	.maxtype        = IFLA_BAREUDP_MAX,
764 	.policy         = bareudp_policy,
765 	.priv_size      = sizeof(struct bareudp_dev),
766 	.setup          = bareudp_setup,
767 	.validate       = bareudp_validate,
768 	.newlink        = bareudp_newlink,
769 	.dellink        = bareudp_dellink,
770 	.get_size       = bareudp_get_size,
771 	.fill_info      = bareudp_fill_info,
772 };
773 
774 static __net_init int bareudp_init_net(struct net *net)
775 {
776 	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
777 
778 	INIT_LIST_HEAD(&bn->bareudp_list);
779 	return 0;
780 }
781 
782 static void __net_exit bareudp_exit_rtnl_net(struct net *net,
783 					     struct list_head *dev_kill_list)
784 {
785 	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
786 	struct bareudp_dev *bareudp, *next;
787 
788 	list_for_each_entry_safe(bareudp, next, &bn->bareudp_list, next)
789 		bareudp_dellink(bareudp->dev, dev_kill_list);
790 }
791 
792 static struct pernet_operations bareudp_net_ops = {
793 	.init = bareudp_init_net,
794 	.exit_rtnl = bareudp_exit_rtnl_net,
795 	.id   = &bareudp_net_id,
796 	.size = sizeof(struct bareudp_net),
797 };
798 
799 static int __init bareudp_init_module(void)
800 {
801 	int rc;
802 
803 	rc = register_pernet_subsys(&bareudp_net_ops);
804 	if (rc)
805 		goto out1;
806 
807 	rc = rtnl_link_register(&bareudp_link_ops);
808 	if (rc)
809 		goto out2;
810 
811 	return 0;
812 out2:
813 	unregister_pernet_subsys(&bareudp_net_ops);
814 out1:
815 	return rc;
816 }
817 late_initcall(bareudp_init_module);
818 
819 static void __exit bareudp_cleanup_module(void)
820 {
821 	rtnl_link_unregister(&bareudp_link_ops);
822 	unregister_pernet_subsys(&bareudp_net_ops);
823 }
824 module_exit(bareudp_cleanup_module);
825 
826 MODULE_ALIAS_RTNL_LINK("bareudp");
827 MODULE_LICENSE("GPL");
828 MODULE_AUTHOR("Martin Varghese <martin.varghese@nokia.com>");
829 MODULE_DESCRIPTION("Interface driver for UDP encapsulated traffic");
830